Ethnopharmacological relevancePreliminary studies showed that Shanlameiye granules are derived from Chimonanthus nitens Oliv. Leaves ameliorate inflammatory responses in mice with Allergic Rhinitis (AR). The essential oil from Chimonanthus nitens Oliv. Leaves (CLO) have been identified as the key active substances in these granules. However, whether CLO constitutes the primary mechanism for the mitigation of AR-related inflammation by these granules has not yet been investigated. Aim of the studyThis experiment was to validate the effects and mechanism of CLO on inflammatory responses in RAW264.7 cells and AR rat model. Materials and methodsAn inflammatory model was induced in RAW264.7 cells by Lipopolysaccharide (LPS) & Interferon-gamma (IFN-γ) stimulation. AR rat model was established using both systemic and local challenges with Ovalbumin (OVA). ResultsIn cell experiments, CLO obviously decreased the secretion of cytokines and inhibited the NF-κB signaling pathway activation. In animal experiments, CLO decreased the number of eosinophils in the blood and lowered the levels of cytokines in nasal lavage fluid (NALF). Additionally, CLO inhibited the expression of STAT6, GATA-3, and p-p65, while increasing the expression of STAT4 and T-bet in the nasal mucosa. ConclusionIn AR rat model, CLO may play an anti-inflammatory role in AR rat model by regulating NF-κB and T-bet/GATA-3 signaling pathways.